The introduction of nitrogen containing fertiliser in the 1860s has drastically improved crop yields. This not only increased the quantity of food that can be produced, but carbon uptake as well.

But due to the high pressure and temperature requirements, nitrogen production is also good for about 1.5 per cent of the world’s energy consumption. But now after a decade-long search researchers have finally made a breakthrough in understanding how nature does it without the high energy needs.

Currently about half of the nitrogen (mostly in the form of proteins) in our bodies comes from the compounds in fertiliser that have travelled up the food chain. The other half is produced by microorganisms in the soil and from there gone up the food chain.

Nitrogenase

Scientists have long known that an enzyme called nitrogenase is responsible for turning airborne nitrogen into a form usable for living organisms. But to reverse-engineer it and mimic nature’s energy efficient way of the process, they needed the exact structure of the enzyme.

Most of the enzyme’s structure was readily found but one atom eluded researchers all over the world and without it the enzyme could not be reproduced. The reason for this is that the particular atom is hidden inside a cluster of iron and molybdenum atoms, which are hard to penetrate with conventional microscopic techniques.

X-rays

But by using a technique called X-ray emission spectroscopy the research team created a chance of less than one in a thousand to identify the metal cluster’s central atom. The technique eventually paid off and the atom was identified as nothing more than carbon.

The discovery ends a decade-long search and finally opens the possibility of reproducing nitrogenase in a lab. Who knows, perhaps this new discovery will eventually lead to a decrease of 1.5 per cent of global energy usage.

© Jorn van Dooren | www.bitsofscience.org